1. Field of the Invention
The present invention relates generally to monitoring.
2. Related Art
Monitoring the status and location of assets, objects, people or animals is a vital part of everyday life. Improving the methodologies for doing this improves in countless ways the lives of everyone. Because of the large number of variables involved with monitoring assets, objects, people or animals, the background of one example embodiment will be described in detail.
Each day, large quantities of freight which has a cumulative value of many millions of dollars are shipped throughout the United States and throughout the world. For example, large quantities of freight are loaded into rail cars and shipped by railroad. Likewise, large quantities of freight are stored in shipping structures and shipped by ship or barge. Even larger quantities of freight are commonly loaded into trailers and shipped by truck.
Due to the quantity and the value of the freight, the owner of the freight as well as the shipper who has assumed custodial responsibility for the freight would like to monitor the position or location of the freight, regardless of its mode of transportation. Moreover, the owner of the freight as well as the shipper would often times also like to monitor the status of the freight while the freight is in route. Monitoring the status of the entire structure in which the freight lies is well known in the art and is described in U.S. Pat. No. 5,917,433 entitled Asset Monitoring System and Associated Method. That patent enables, for example, monitoring the temperature of a refrigerated trailer in transport to insure that the refrigerated products stored within the trailer are appropriately chilled. However, due to power limitations of the current state of the art as well as multipath problems of having a plurality of radio transmitters transmitting within a structure, the ability to monitor individual objects within a structure has been unachieved.
The earliest method of monitoring the progress of a tractor-trailer required the driver to periodically park the tractor and inspect the contents of the trailer and to telephone the central station or dispatcher in order to report the present location of the tractor-trailer and to obtain updated delivery information and status of the cargo. By requiring the driver to periodically telephone the central station or dispatcher, however, the average speed of the tractor-trailer was significantly reduced. In addition, the information relating to the present location of the tractor-trailer provided by the drivers was sometimes inaccurate, due either to inadvertent mistakes or attempts by the driver to intentionally mislead the dispatcher regarding the progress of the tractor-trailer.
As a result, more sophisticated monitoring systems have been developed which allow communications to be established between the driver of a tractor and a central station or dispatcher, while the tractor-trailer continues along its route. These monitoring systems can also include a receiver mounted to the tractor for communicating with the Global Positioning System (GPS) satellites in order to determine the present location ofthe tractor-trailer. The monitoring systems can then transmit information relating to the present position of the tractor-trailer to the central station or dispatcher without requiring the driver to stop the tractor-trailer and to telephone the central station or dispatcher.
Conventional monitoring systems can also include one or more sensors for monitoring predetermined engine parameters, such as the oil pressure or engine temperature. Data representing these parameters can then be transmitted to the central station or dispatcher on an event-triggered, i.e., emergency basis, on a regularly scheduled basis or as requested or polled. In addition, conventional monitoring systems can include one or more sensors mounted within or upon the trailer in order to monitor predetermined conditions within the trailer, such as the temperature within a refrigerated trailer. This is not problematic with conventional radios if a single sensor is monitoring and transmitting information on single criteria, for example temperature. However, if there are a number of different criteria to be monitored on individual cargo items, for the reasons subsequently articulated, conventional wireless transmission are inadequate.
In a like fashion, these tractor-based monitoring systems can then transmit the sensory signals provided by the trailer sensors to the central station or dispatcher. Accordingly, conventional monitoring systems can monitor the location of the tractor, while monitoring a very limited number of predetermined engine or trailer conditions as the tractor-trailer continues along its route.
As has been discussed, a variety of monitoring systems have been developed which are designed to monitor the location and, in some instances, the status of freight during shipment. However, all of these prior systems have in some way relied on conventional radio and communication systems with the concomitant limitations.
For example, conventional radio systems are band and power limited. Further, they are subject to multipath effects and perform poorly in many environments. Because of these aforementioned limitations conventional monitoring systems typically only monitor large structures such as tractor trailers or shipping cargo trailers. Multi-path effects and limited bandwidth prevent placing asset monitoring transmitters within the shipping structures themselves.
The prior system limitations can be exemplified. A tractor trailer may be shipping very valuable cargo across the country and it is desired to monitor the location and status of the cargo. The cargo may be biohazardous material that must be maintained at a certain temperature. With current systems, only the overall temperature and position of the trailer can be ascertained. If an individual canister is removed or if its individual temperature exceeds a predetermined limit, it could not be determined. Consequently, there has been a persistent need in the asset monitoring industry to not only track and monitor the status of a structure as a whole, but also to track and monitor individual assets, objects, people or animals within that structure.
It is therefore an object ofthe present invention to provide an asset, object, person or animal monitoring system and associated method for monitoring assets, objects, people or animals utilizing impulse radio techniques.
It is another object of the present invention to provide an impulse radio asset, object, people or animal monitoring system and associated method for monitoring the status of assets, objects, people or animals without the use of external power supplied to the transmitters on the contents of the structure.
It is another object of the present invention to provide an impulse radio asset, object, people or animal monitoring system and associated method for monitoring the status of assets, objects, people or animals wherein the impulse radio transmitters can vary its transmission duty cycles, by both manual and automatic adjustment, to adapt to varied requirements.
These and other objects are provided, according to the present invention, by an asset, object, people or animal monitoring system and associated method which includes an asset, object, people or animal monitor for providing a remotely located central station with information relating to assets, objects, people or animals which may be located in a structure. The assets, objects. people or animal monitor also includes a controller for controlling its operations, an impulse radio receiver in communication with said controller and at least one impulse radio transmitter attached to the assets, objects, people or animals to be monitored and transmitting information to said receiver regarding the status and location of the assets, objects, people or animals.
The asset, object, people or animal monitoring system and, in one embodiment, the asset, object, people or animal monitor, include communications means, such as a communications transceiver, for establishing a first communications link between the asset, object, people or animal monitor and the remotely located central station. The communications means of the asset, object, people or animal monitor is adapted to receive information from the impulse radio receiver and transmit information, such as the location of the structure, the status of the structure, the status of the structure""s contents and the effective time and date of the location and status information, to the central station via the first communications link.
The transmitters of one advantageous embodiment of the present invention interface with a sensor that determines various required information about the individual contents of the structure; such as temperature, humidity, physical presence, volume, radio activity or any other required parameters. Each sensor is associated with the individual contents of the structure and is adapted to provide a predetermined type of sensory signal. For example, each sensor can be adapted to provide a respective interrupt signal to the sensor interface, such as in instances in which the sensed condition or event falls outside of an acceptable range. The transmission duty cycle of the transmitters can be manually or automatically modified to accommodate the varying needs of the shipper. For example, if the asset to be monitored will be in a structure for extended periods of time because of storage requirements or long distance traveled, the transmission duty cycle will be minimal (possibly a transmission every hour). This will greatly increase the battery life of the transmitters. If, however, the objects to be monitored require constant monitoring, a very short (e.g., 10-second) transmission duty cycle can be implemented.
Based on the interrupt signals provided by the sensors, transmitted by the transmitters and received by the receivers which are interfaced with the asset, object, people or animal monitor, the asset, object, people or animal monitor can transmit a warning signal to the central station to alert the dispatcher to the sensed condition or event. In addition to, or instead of, providing interrupt signals, the sensors can provide sensory signals that are indicative of the condition or event being monitored. The asset, object, people or animal monitor can then process and/or store these sensory signals and can transmit these sensory signals to the central station, such as in instances in which the asset, object, people or animal monitor determines that the sensory signals fall outside of an acceptable range.
The asset, object, people or animal monitoring system can also include an operator interface that may, for example, be mounted within the cab of a tractor or truck. According to this advantageous embodiment, the communications means can also establish a second communications link between the asset, object, people or animal monitor and the operator interface. Thus, the asset, object, people or animal monitor and the operator or driver can exchange or transmit predetermined types of information. For example, the asset, object, people or animal monitor can provide information relating to the present location of the structure and the status of the structure and its individual contents, such as by providing warning signals to the operator if the sensed conditions or events fall outside of an acceptable range. In addition, the asset, object, people or animal monitor can pass messages between the central station and the operator interface, such as to provide warnings, revised directions or an updated itinerary.
The asset, object, people or animal monitor can also include position-determining means, such as a receiver, for receiving externally supplied location data indicative of the present position of the structure. For example, the position receiver can include a GPS receiver for receiving location data from a plurality of GPS satellites from which the present position of the structure can be determined. Accordingly, the asset, object, people or animal monitor can transmit information identifying the present position of the structure to this central station via the first communications link.